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Meningiomas are the most common primary intracranial tumors in adults and are increasing in incidence due to the aging population and increased access to neuroimaging. While most exhibit nonmalignant behavior, a subset of meningiomas are biologically aggressive and are associated with treatment resistance, resulting in significant neurologic morbidity and even mortality. In recent years, meaningful advances in our understanding of the biology of these tumors have led to the incorporation of molecular biomarkers into their grading and prognostication. However, unlike other central nervous system (CNS) tumors, a unified molecular taxonomy for meningiomas has not yet been established and remains an overarching goal of the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy-Not Official World Health Organization (cIMPACT-NOW) working group. Additionally, clinical equipoise still remains on how specific meningioma cases and patient populations should be optimally managed. To address these existing gaps, members of the International Consortium on Meningiomas including field-leading experts, have prepared this comprehensive consensus narrative review directed toward clinicians, researchers, and patients. Included in this manuscript are detailed overviews of proposed molecular classifications, novel biomarkers, contemporary treatment strategies, trials on systemic therapies, health-related quality-of-life studies, and management strategies for unique meningioma patient populations. In each section, we discuss the current state of knowledge as well as ongoing clinical and research challenges to road map future directions for further investigation.

PURPOSE: NF2-related schwannomatosis (NF2) is characterized by bilateral vestibular schwannomas (VS) often causing hearing and neurologic deficits, with currently no FDA-approved drug treatment. Pre-clinical studies highlighted the potential of mTORC1 inhibition in delaying schwannoma progression. We conducted a prospective open-label, phase II study of everolimus for progressive VS in NF2 patients and investigated imaging as a potential biomarker predicting effects on growth trajectory. METHODS: The trial enrolled 12 NF2 patients with progressive VS. Participants received oral everolimus daily for 52 weeks. Brain imaging was obtained quarterly. As primary endpoint, radiographic response (RR) was defined as ≥ 20% decrease in target VS volume. Secondary endpoints included other tumors RR, hearing outcomes, drug safety and quality of life (QOL). RESULTS: Eight participants completed the trial and four discontinued the drug early due to significant volumetric VS progression. After 52 weeks of treatment, the median annual VS growth rate decreased from 77.2% at baseline to 29.4%. There was no VS RR and 3 of 8 (37.5%) participants had stable disease. Decreased or unchanged VS volume after 3 months of treatment was predictive of stabilization at 12 months. Seven of eight participants had stable hearing during treatment except one with a decline in word recognition score. Ten of twelve participants reported only minimal changes to their QOL scores. CONCLUSIONS: Volumetric imaging at 3 months can serve as an early biomarker to predict long-term sensitivity to everolimus treatment. Everolimus may represent a safe treatment option to decrease the growth of NF2-related VS in patients who have stable hearing and neurological condition. TRN: NCT01345136 (April 29, 2011).

Background/Objectives: Vestibular schwannomas (VSs), also called acoustic neuromas, are benign tumors affecting the vestibulocochlear nerve, often leading to hearing loss and balance issues. This condition is particularly challenging in patients with neurofibromatosis type 2 (NF2), where VSs tend to develop bilaterally. Conventional treatments, such as surgery and radiotherapy, although effective, carry risks like hearing loss and nerve damage. Bevacizumab, a VEGF-targeting monoclonal antibody, has emerged as a less invasive treatment option, showing potential for tumor volume reduction and hearing preservation. This systematic review aims to assess the efficacy of bevacizumab in controlling tumor volume, preserving hearing, and identifying associated adverse events. Methods: A comprehensive systematic review was performed using PRISMA guidelines. PubMed and Cochrane Library databases were searched for studies evaluating the effects of bevacizumab on VS, focusing on key outcomes like tumor volume reduction, hearing preservation, and adverse events. Data extraction and quality assessment were independently conducted by two reviewers using the Newcastle-Ottawa Scale. Results: Nine studies involving 176 patients were included. Bevacizumab showed a partial tumor volume reduction (≥20%) in 40% of cases and disease stabilization in 50%, while 10% experienced tumor progression. Hearing outcomes revealed improvement in 36% of patients, stabilization in 46%, and deterioration in 18%. Severe adverse effects, including hypertension and thromboembolic events, occurred in 13% of patients, while 18% reported no side effects. Tumor regrowth was observed in some patients after treatment discontinuation, emphasizing the need for long-term monitoring. Conclusions: Bevacizumab demonstrates effectiveness in managing VS, particularly in NF2 patients, by reducing tumor size and preserving hearing in a substantial proportion of cases. However, the variability in patient response and the risk of adverse events underscore the need for individualized treatment approaches and further research, including randomized controlled trials, to optimize its clinical application. [ABSTRACT FROM AUTHOR]

Background: Survival after meningioma surgery is often reported with inadequate allowance for competing causes of death. Methods: We processed the Système National des Données de Santé, the French administrative medical database to retrieve appropriate patients' case of surgically treated meningiomas. The Pohar Perme relative survival (RS) method was implement. Results: A total of 28,778 patients were identified between 2007 and 2017 of which 75% were female. Median age at surgery 59 years. Cranial convexity was the most common (24.7%) location and, benign meningioma represented 91.5% of all meningioma. Median follow-up was 3.5 years interquartile range [3.4–3.5]. At data collection, 2,232 patients were dead. The five-year survival relative to the expected survival of an age- and gender-matched French standard population was 96.2% 95% confidence interval (CI)[95.7–96.8]. Meningioma absolute excess risk of death was 973/100,000 person-years 95%CI[887–1068] (p<.001). The related standardised mortality ratio was 1.8 95%CI[1.7–1.9] (p<.001). In the adjusted model, male gender (hazard ratio [HR] =1.39, 95%CI[1.27–1.54], p<.001), age at surgery (HR=0.97, 95%CI[0.97–0.97], p <.001), type 2 neurofibromatosis (HR=2.95, 95%CI[1.95–4.46], p <.001), comorbidities HR=1.39, 95%CI[1.36–1.42], p <.001), location (HR=0.8, 95%CI[0.67–0.95], p=.0111), pre-operative embolization, (HR=1.3, 95%CI[1.08–1.56], p=.00507), cerebro-spinal fluid shunt, (HR=2.48, 95%CI[2.04–3.01], p <.001), atypical (HR=1.3, 95%CI [1.09–1.54], p=.00307) or malignant histology (HR=1.86, 95%CI[1.56–2.22], p<.001), redo surgery (HR=1.19, 95%CI[1.04–1.36], p=.0122) and radiotherapy (HR=1.43, 95%CI[1.26–1.62], p <.001) were established as independent predictors of RS. Conclusion: This unique study highlights the excess mortality associated with meningioma disease. Many factors such as gender, age, location, histopathological grading, redo surgery influence the RS. [ABSTRACT FROM AUTHOR]

We describe a case of a 24 year old female who came with complaint of bilateral tinnitus, profound hearing loss, and weakness in both lower limbs which on imaging work up showed unilateral acoustic schwannoma, and spinal extramedullary intradural lesions at D8-D9 level giving the classical features of neurofibromatosis II along with cafe au lait spots, axillary freckling, cutaneous neurofibromas, which are unique to NF1. The purpose of this report is to discuss the study of a patient with classical features of both NF-I and NF-II, emphasizing the need for surveillance regarding sporadic mutations seen in NF I AND NF II genes, as well as genetic mosaicism to be kept in mind when diagnosing such patients. [ABSTRACT FROM AUTHOR]

Neurofibromatosis type 2 (NF2), also known as NF2‐related schwannomatosis (SWN), is a rare dominantly inherited genetic disorder mainly characterized by the presence of vestibular schwannomas (VSs) in addition to a range of other tumors that affect both the central and peripheral nervous systems. These tumors include cranial, spinal, peripheral nerve, and intradermal schwannomas, cranial and spinal meningiomas, and intrinsic central nervous system (CNS) tumors, usually spinal ependymomas. Juvenile cataracts are also common in patients with NF2, with most symptoms at presentation being hearing loss and visual disturbances. We present the case of a previously healthy 12‐year‐old girl who presented with postprandial right upper quadrant pain and was found to have a large hydrops of the gallbladder on ultrasound scan of the abdomen. Pathology of the gallbladder post laparoscopic cholecystectomy showed diffuse involvement of the gallbladder by a benign nerve sheath tumor that was suggestive of schwannoma. Further testing confirmed the diagnosis of NF2. This case helps shed light on unusual NF2 symptoms and underscores the importance of recognizing atypical presentations for timely intervention and management. It also adds value to a multidisciplinary approach in diagnosing and managing NF2. [ABSTRACT FROM AUTHOR]

NF2-related Schwannomatosis (NF2-SWN) is an autosomal dominant disease with full penetrance. Increasing data shows that long non-coding RNAs (lncRNA) can act as competitive endogenous RNAs (ceRNA), regulating target gene expression. This study aims to investigate lncRNAs in NF2-SWN that may be involved in regulating NF2 pathogenic genes. Data were collected from three patients with NF2-SWN, including medical records, physical examination, imaging, pathology, and RNA from the tumor and adjacent tissues. differentially expressed genes (DEGs) between the two groups were screened by conducting gene differential analysis on the sequenced data. Next, GO & KEGG enrichment analysis was performed on DEGs, and an association network between lncRNA and NF2 was established to identify regulatory lncRNA. Finally, qRT-PCR was used to substantiate the expression patterns of critical lncRNAs and NF2 in NF2-SWN. Sequencing revealed 6433 DEGs involved in key biological processes and pathways, such as axon guidance, intracellular signal transduction, cell migration, phosphorylation, cell adhesion molecules, taste transduction, axon guidance, and ErbB signaling pathways, etc. The ceRNA correlation network identified four lncRNAs (CADM3-AS1, MTMR9LP, LOC101929536, PRDM16-DT) that may regulate the NF2 gene. As expected, qRT-PCR results revealed that compared with the control group, the expression levels of L0C10929536 and PRDM16-DT in the tumor group were significantly increased. In contrast, the expression levels of MTMR9LP and CADM3-AS1 genes were decreased. Four identified lncRNAs could be crucial for NF2-SWN development, potentially serving as diagnosis biomarkers or therapeutic targets. This study contributes to the understanding of NF2-SWN's molecular mechanism. [ABSTRACT FROM AUTHOR]

BACKGROUND: Intracochlear schwannomas (ICSs) are a subtype of intralabyrinthine schwannomas, completely located in the cochlear lumen. ICSs are particularly rare in the pediatric population. Putative diagnosis is made on the basis of magnetic resonance findings with signal characteristics that should remain the same at follow-up imaging. METHODS: A retrospective review was performed searching for pediatric patients affected by ICS treated at the Otolaryngology Department, Ospedale Ramazzini, Carpi (Italy), and Otolaryngology and Otoneurosurgery Department, Azienda Ospedaliero-Universitaria di Parma, (Italy). A scoping literature review of the period January 2000 - June 2024 was performed. RESULTS: Two cases of ICS in pediatric patients are described. Neither family history nor genetic signs of neurofibromatosis type II were found. A single report was identified in the literature review. Data analysis resumes the pooled data of the latter case and the authors' patients. The most common symptom at presentation was progressive sensorineural hearing loss (66%). Mean pure tone average at diagnosis was 74.2 dB. Intracochlear location was in the basal turn in 2 cases and in the apical and middle turns in the third patient. All cases initially underwent a "wait and scan" strategy. The mean follow-up time was 23.3 months. CONCLUSION: Management planning of pediatric ICSs should be accurate as surgical removal may require partial or total cochlear demolition, resulting in vestibular dysfunction and precluding future positioning of a cochlear implant. Close clinical and radiological follow-up with serial MRI scans allows to evaluate both symptom progression and rate of growth, in order to provide patients with the best therapeutic option. [ABSTRACT FROM AUTHOR]

Meningioangiomatosis (MAM) remains a poorly understood lesion responsible for epileptic disease. In the past, MAM was primarily described in the context of neurofibromatosis type 2 before being mainly reported sporadically. Moreover, the malformative or tumoral nature is still debated. Because a subset of MAM are associated with meningiomas, some authors argue that MAM corresponds to an infiltration pattern of these tumors. For these reasons, MAM has not been added to the World Health Organization (WHO) Classification of Central Nervous System Tumors as a specific entity. In the present study, we characterized a series of pure MAM (n = 7) and MAM associated with meningiomas (n = 4) using histopathology, immunohistochemistry, genetic (fluorescent in situ and DNA sequencing analyses), and epigenetic (DNA‐methylation profiling) data. We evidenced two distinct morphological patterns: MAM with a fibroblastic‐like pattern having few lesional cells, and MAM with a more cellular pattern. A subset was associated with the genetic alterations previously reported in meningiomas (such as a KMT2C mutation and a hemizygous deletion of chromosome 22q including the NF2 gene). The DNA‐methylation profile, using a t‐distributed stochastic neighbor embedding analysis, evidenced that MAM (pure or associated with meningiomas) clustered in a separate group from pediatric meningiomas. The present results seem to suggest that MAM represents a neoplastic lesion and encourage the further study of similar additional series so that it may be included in a future WHO classification. [ABSTRACT FROM AUTHOR]

Abstract Background NF2-related schwannomatosis (NF2) is associated with various tumors of the central and peripheral nervous system. There is a wide range of disabilities these patients may suffer from and there is no validated clinical classification for disease severity. We propose a clinical classification consisting of three severity grades to assist in patient management. Methods Patient records from 168 patients were screened for most common diagnoses with severe impact on everyday tasks, social interactions and life expectancy. Eight main categories were identified. One point was assigned to each category. Three severity grades were differentiated as follows: grade 1 (mild NF2): 0 points; grade 2 (moderate NF2): < 3 points; grade 3 (severe NF2): ≥ 3 points. This grading system was then evaluated with respect to inter-rater reliability and clinical significance. Results The patients were grouped according to our new clinical grading system into grade 1 in 48% (n = 80), grade 2 in 43% (n = 72), and grade 3 in 10% of patients (n = 16). There was substantial inter-rater reliability between 3 raters with different levels of clinical experience (Fleiss’ kappa = 0.62). The severity grades correlated significantly with hospitalization, number of operations and dependency on implants (such as cochlear implant, auditory brain-stem implants or ventriculoperitoneal shunts). Conclusions Clinical disease severity of NF2 patients is reflected in a simplified and rater-independent score with three grades. The score facilitates communication for medical personnel of varying experience and backgrounds, and adds a clinical tool to decision-making and research.

Schwann cell tumors are the most common cancers of the peripheral nervous system and can arise in patients with neurofibromatosis type-1 (NF-1) or neurofibromatosis type-2 (NF-2). Functional interactions between NF1 and NF2 and broader mechanisms underlying malignant transformation of the Schwann lineage are unclear. Here we integrate bulk and single-cell genomics, biochemistry, and pharmacology across human samples, cell lines, and mouse allografts to identify cellular de-differentiation mechanisms driving malignant transformation and treatment resistance. We find DNA methylation groups of Schwann cell tumors can be distinguished by differentiation programs that correlate with response to the MEK inhibitor selumetinib. Functional genomic screening in NF1-mutant tumor cells reveals NF2 loss and PAK activation underlie selumetinib resistance, and we find that concurrent MEK and PAK inhibition is effective in vivo. These data support a de-differentiation paradigm underlying malignant transformation and treatment resistance of Schwann cell tumors and elucidate a functional link between NF1 and NF2.

BackgroundCase PresentationConclusionNeurofibromatosis type-2-related schwannomatosis (NF2-SWN, formerly neurofibromatosis type 2) is a rare genetic disorder marked by the development of multiple nervous system tumors.We report a 21-month-old female patient who presented for left eye deviation. Upon examination, intermittent exotropia and a fundus mass were detected. Wide field fundus examination revealed the presence of a combined hamartoma involving the optic nerve and retina. This finding was supported by MRI highlighting the lesion’s characteristics. The patient’s father and other relatives on the paternal side displayed symptoms of NF2-SWN, evident through the presence of acoustic neuroma, although they did not exhibit any ocular symptoms. DNA analysis revealed a novel loss-of-function mutation in exon 15 of the NF2 gene (NM_000268.3: c.1627_1628del, p.Lys543Aspfs *21) in both the patient and her father at a heterozygous state. By the age of three, her vision worsened, and optical coherence tomography showed vitreomacular traction and intraretinal fluid surrounding the lesion.This case underscores the need to consider NF2- SWN in peripapillary hamartoma diagnoses and highlights the importance of genetic testing for early detection and management. [ABSTRACT FROM AUTHOR]

Purpose: This retrospective monocentric study aimed to evaluate long-term auditory brainstem implant (ABI) function in patients with neurofibromatosis type 2, and to investigate the prognostic factors for ABI use. Methods: Between 1997 and 2022, 27 patients with at least five years of follow-up underwent implantation with 32 ABIs. At 1- and 5-years post-implantation and at last follow-up, ABIs were classified as used or non-used and the size of the ipsilateral tumor was recorded. For patients who used their ABIs, we assessed speech perception (disyllabic words, MBAA sentences) in quiet conditions with the ABI only, by lip-reading (LR), and with a combination of the two (ABI + LR). Hearing improvement was calculated as Δ ABI = (ABI + LR)–LR scores. Predictive factors for ABI use were analyzed. Results: One year post-implantation, 74% patients were ABI-users and 66% of the ABIs were used. Two of these patients were non-users at five years, and another two at last follow-up (14 ± 5.2 years); 54% of the patients were ABI-users at last follow-up. Δ ABI revealed a hearing improvement of 32–41% (disyllabic words) and 28–37% (MBAA sentences). Among 16 ABIs with at least LR improvement at 1-year post-implantation, 4 decreased their performance, coinciding with a large growing ipsilateral tumor in 3/4 ABIs. We identified no significant prognostic factors for ABI use. Conclusions: ABIs are indicated in case of bilateral deafness with a non-functional cochlear nerve. Half the patients with ABIs used their implants and auditory performance remained stable over time, except in cases of ipsilateral tumor growth. [ABSTRACT FROM AUTHOR]

The article from GEN Biotechnology discusses Recursion's innovative approach to AI and machine learning in drug development. Recursion aims to revolutionize the drug discovery process by utilizing its Recursion Operating System, which integrates hardware, software, datasets, and proprietary tools to explore biology's complex search space. The company plans to announce clinical data from several pipeline candidates, including REC-994 for cerebral cavernous malformation, and is set to merge with Exscientia to further enhance its capabilities. Recursion's CEO, Chris Gibson, emphasizes the importance of AI in improving the efficiency and success rate of drug development, aiming to challenge the industry's low success rate through innovative approaches. [Extracted from the article]

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer deaths worldwide. Significantly activated uridine nucleotide and fatty acid metabolism in HCC cells promote malignant proliferation and immune evasion. Herein, it is demonstrated that the tripartite motif 65 (TRIM65) E3 ubiquitin‐protein ligase, O‐GlcNAcylated via O‐GlcNAcylation transferase, is highly expressed in HCC and facilitated metabolic remodeling to promote the accumulation of products related to uracil metabolism and palmitic acid, driving the progression of HCC. Mechanistically, it is showed that TRIM65 mediates ubiquitylation at the K44 residue of neurofibromatosis type 2 (NF2), the key protein upstream of classical Hippo signaling. Accelerated NF2 degradation inhibits yes‐associated protein 1 phosphorylation, inducing aberrant activation of related metabolic enzyme transcription, and orchestrating metabolic and immune advantages. In conclusion, these results reveal a critical role for the TRIM family molecule TRIM65 in supporting HCC cell survival and highlight the therapeutic potential of targeting its E3 ligase activity to alter the regulation of proteasomal degradation. [ABSTRACT FROM AUTHOR]

Cutaneous angiofibroma is a group of lesions that show similar histological features, but different clinical findings and can be divided into four subgroups: fibrous papule, adenoma sebaceum, periungual fibroma (Koenen tumors) and pearly penile papules of the penis. Facial angiofibromas are one of the diagnostic clinical findings of tuberous sclerosis. Although less common, it has also been reported in cases with multiple endocrine neoplasia Type 1, Birt-Hogg-Dubé syndrome, neurofibromatosis Type 2 and Cowden syndrome. It may also occur isolated without accompanying any systemic syndrome, as in our case. There is a report of four cases with bilateral multiple facial cutaneous angiofibromas that are not accompanied by any syndrome, and no other publication has been found in the literature. In this report, a twelveyear-old male patient with bilateral facial cutaneous angiofibromas, unaccompanied by systemic findings, is presented with its clinical, genetic, dermoscopical and histopathological findings. [ABSTRACT FROM AUTHOR]

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Objectives Distinguishing between sporadic and germline/mosaic NF2- related schwannomatosis is important to ensure that patients have appropriate long-term care. With this report, we describe a unique case of a patient with 4 ipsilateral schwannomas and identify a combination of sequencing modalities that can accurately diagnose mosaic NF2- related schwannomatosis. Methods We present a 32-year-old woman with a familial history of vestibular schwannoma in her father and right-sided schwannomas involving the apical and basal turns of cochlea, lateral semicircular canal, and internal auditory canal (IAC). Genetic analysis of blood and frozen tissue from 2 tumors (intralabyrinthine and IAC tumors) was performed using next-generation sequencing (NGS), multiplex ligation-dependent probe amplification (MLPA), and optical genome mapping (OGM). Results Germline testing for NF2, LZTR1, and SMARCB1 was negative. Tumor genetic testing revealed a shared NF2 pathogenic variant between the 2 tumors ("first hit") but distinct "second hit" NF2 variants, including mosaic loss of chromosome 22 in the IAC tumor seen only with OGM, consistent with mosaic NF2- related schwannomatosis. Conclusions Multimodality sequencing, including NGS, MLPA, and OGM, was required to ensure appropriate diagnosis of mosaic NF2- related schwannomatosis in this patient. A similar approach can be used for other patients with multiple ipsilateral tumors and suspected tumor predisposition. [ABSTRACT FROM AUTHOR]

Objectives: To determine the natural history of hearing loss and tumor volume in patients with untreated neurofibromatosis type 2 (NF2)-related schwannomatosis. Moreover, we statistically examined the factors affecting hearing prognosis. Methods: This retrospective cohort study was conducted on 37 ears of 24 patients with NF2-related vestibular schwannomatosis followed up without treatment for more than 1 year. We obtained detailed chronological changes in the PTA and tumor volume in each case over time, and the rate of change per year was obtained. Multivariate analysis was also conducted to investigate factors associated with changes in hearing. Results: The average follow-up period was approximately 9 years, and hearing deteriorated at an average rate of approximately 4 dB/year. The rate of maintaining effective hearing decreased from 30 ears (81%) at the first visit to 19 ears (51%) at the final follow-up. The average rate of change in tumor growth for volume was approximately 686.0 mm3/year. This study revealed that most patients with NF2 experienced deterioration in hearing acuity and tumor growth during the natural course. A correlation was observed between an increase in tumor volume and hearing loss (r = 0.686; p < 0.001). Conclusions: Although the hearing preservation rate in NF2 cases is poor with the current treatment methods, many cases exist in which hearing acuity deteriorates, even during the natural course. Patients with an increased tumor volume during the follow-up period were more likely to experience hearing deterioration. Trial registration number 20140242 (date of registration: 27 October 2014). [ABSTRACT FROM AUTHOR]

The article in Pediatric Dermatology discusses a case of an asymptomatic nasal nodule in a 13-year-old girl, which was diagnosed as a schwannoma. Schwannomas are benign tumors composed of Schwann cells and can occur in any age group, although they are rare in adolescents. The article highlights the pathogenesis, clinical presentation, differential diagnosis, and treatment options for schwannomas, emphasizing the importance of histopathological examination in diagnosis. The study was supported by grants from the National Natural Science Foundation of China and Shenzhen Science and Technology Planning Project. [Extracted from the article]

A 40-year-old man presented with two asynchronous spinal cord tumors, diagnosed as spinal ependymoma and myxopapillary ependymoma. The tumors were histologically distinct, requiring molecular analysis for accurate diagnosis. Surgical intervention was crucial for treatment, highlighting the importance of molecular diagnostics in guiding therapeutic decisions for rare CNS tumors. The case study underscores the need for continuous evaluation of treatment options for such tumors. [Extracted from the article]

Neurofibromatosis type 2 is a genetic disorder that results in the formation and progressive growth of schwannomas, ependymomas, and/or meningiomas. The NF2 gene encodes the Merlin protein, which links cell cortical elements to the actin cytoskeleton and regulates a number of key enzymes including Group I p21-activated kinases (PAKs), the Hippo-pathway kinase LATS, and mTORC. While PAK1 and PAK2 directly bind Merlin and transmit proliferation and survival signals when Merlin is mutated or absent, inhibition of Group 1 PAKs alone has not proven sufficient to completely stop the growth of NF2-deficient meningiomas or schwannomas in vivo, suggesting the need for a second pathway inhibitor. As the Hippo pathway is also activated in NF2-deficient cells, several inhibitors of the Hippo pathway have recently been developed in the form of YAP-TEAD binding inhibitors. These inhibitors prevent activation of pro-proliferation and anti-apoptotic Hippo pathway effectors. In this study, we show that PAK inhibition slows cell proliferation while TEAD inhibition promotes apoptotic cell death. Finally, we demonstrate the efficacy of PAK and TEAD inhibitor combinations in several NF2-deficient Schwannoma cell lines. [ABSTRACT FROM AUTHOR]

Objectives: The behavior of orbital meningiomas is difficult to predict. The p53 tumor suppressor gene mutation and the neurofibromatosis 2 gene's inactivation in the merlin formation are two of the several mechanisms that contribute to the development of tumors. This considers the comparison of merlin and p53 expression as an inclination to evaluate the orbital meningiomas. Materials and Methods: This investigation is an observational expository considered within the shape of cross-sectional (cross-sectional). The samples/objects of this study were 44 patients with orbital meningioma who had a clinical, radiological, and histopathological diagnosis at the anatomical pathology laboratory at Cicendo Eye Hospital and Hasan Sadikin Bandung in 2017-2020, then an immunohistochemical examination of merlin and p53 expression was performed. Results: The study indicated that there was no relationship between p53 expression and orbital meningioma grading, also there is no relationship between merlin expression and orbital meningioma grading. However, based on the analysis test results, grade 3 orbital meningiomas tended to have a positive p53 expression rather than a negative expression and tend to have a negative merlin expression instead of a positive. Conclusion: Meningiomas with negative merlin expression have a tendency to express positive p53. Likewise, the higher grade (grade 3) tends to express positive p53 and negative merlin, which may play a key role in tumorigenesis of orbital meningioma, hence, an added value for clinical information and behavioral descriptions of orbital meningioma itself. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusions Neurofibromatosis type 2 (NF2) is a rare autosomal dominant syndrome with a predisposition to the development of central nervous system tumors, ophthalmic manifestations, and dermatological lesions. The latter are present in 70–95% of patients and can precede the evolution of other tumors. However, they are not included in the diagnostic criteria and are frequently undervalued during follow‐up.An observational cross‐sectional study characterizing cutaneous lesions in a cohort of NF2 patients was carried out. Dermatological examinations were performed, and lesions were classified into neural cutaneous tumors (superficial, SNCT, and deep, DNCT), hyperpigmented patches (HyperP), and hypopigmented patches (HypoP). The Dermatology Life Quality Index (DLQI) and EQ‐5D questionnaires were applied to evaluate the impact on quality of life.Nineteen patients with a mean age of 36 years were included. Sixteen (84%) patients had cutaneous lesions, mostly developed 10 or more years before the diagnosis. SNCT, DNCT, and HyperP showed similar frequencies (58%). HypoP were observed in only one patient. HyperP developed, on average, earlier than NCT (9.6 vs. 16.5 SNCT, 17.0 DNCT; years). The excised lesions had different histological patterns, including neurofibromas, schwannomas, and a hybrid tumor. Most patients reported a low impact of cutaneous manifestations on the quality of life (DLQI 0 or 1).Cutaneous lesions are frequent in NF2 and may precede the diagnosis by several years. Their identification is important to establish the diagnosis earlier and potentially reduce morbidity and mortality. [ABSTRACT FROM AUTHOR]

Introduction CyberKnife (CK) radiosurgery is a treatment strategy for vestibular schwannoma (VS). Objectives To evaluate hearing preservation (HP) after CK for VS. Data Synthesis The study was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement, and it was registered at the International Prospective Register of Systematic Reviews (PROSPERO, under number CRD42021250300). The inclusion criteria were based on the population, intervention, comparison, outcome, timing and study design (PICOTS) strategy: population – patients with VS; intervention – CK; Comparison – none; Outcome – serviceable HP defined by Gardner and Robertson as grades I or II, or by the American Academy of Otolaryngology and Head and Neck Surgery as classes A or B; timing – mean follow-up longer than 1 year; and study design – retrospective or prospective studies. The exclusion criteria were: studies not published in English; studies published before January 2000 and after October 2021; and studies only including patients with neurofibromatosis type 2 or submitted to a previous treatment. The PubMed/MEDLINE, EMBASE, Web of Science, Cochrane Library, LILACS, and IBECS databases were used and last searched on October 27th, 2021. Statistical heterogeneity was assessed using I2 statistics. The appraisal checklist was used to assess the risk of bias in the included studies. A total of 222 studies were analyzed, and 13 were included in the synthesis, which represents 493 participants with serviceable hearing before intervention. The mean HP rate after CK using a random effects model was of 68% (95% confidence interval [95%CI]: 59–76%) at a mean follow-up of 42.96 months. Conclusion The longer follow-up period was associated with a lower HP rate after CK radiosurgery for VS in the qualitative synthesis. [ABSTRACT FROM AUTHOR]

Sporadic vestibular schwannomas (VSs) are rare in children. When occurred in the pediatric population, they usually appear bilaterally and are related to neurofibromatosis type 2 (NF2). The current study reports a 4-year-old boy without family history of VS or NF2 who presented with a large (5.7-cm) VS involving the right cerebellopontine angle and internal auditory canal. Through seven-staged surgical interventions and two stereotactic γ‑knife radiosurgery, the disease was stabilized. At 2-year follow-up, the child had right ear hearing loss, grade IV facial palsy, and normal motor function and gait. No definite evidence of gene mutation regarding NF2 can be identified after sequence analysis and deletion/duplication testing. This case highlights the significance of considering the possibility of sporadic VSs, even in very young children. It emphasizes the importance of not overlooking initial symptoms, as they may indicate the presence of a large tumor and could potentially result in delayed diagnosis. [ABSTRACT FROM AUTHOR]

Neurofibromatosis is one of the most common genetic diseases. It is inherited in an autosomal dominant manner. It is divided into two genetically distinct subtypes, characterized by multiple skin lesions and tumors of the peripheral and central nervous system. Neurofibromatosis type 1, or Recklinghausen's disease, is the most common phakomatosis. The disease is genetically determined by a mutation of the neurofibromin-1 gene on chromosome 17. Neurofibromatosis type 2 accounts for 3% of all cases. The disease is genetically determined - caused by a mutation of the neurofibromin-2 gene on chromosome 22. The diagnostic and therapeutic process of neurofibromatosis is a major challenge for clinicians. Given the complexity of the problem, we have reviewed the literature on the diagnostic and therapeutic possibilities of the disease. [ABSTRACT FROM AUTHOR]

BACKGROUND: NF2-reIated schwannomatosis (NF2-SWN, formerly called neurofibromatosis type 2) is a tumor predisposition syndrome that is manifested by multiple vestibular schwannomas, nonvestibular schwannomas, meningiomas, and ependymomas. The condition is relentlessly progressive with no approved therapies. On the basis of preclinical activity of brigatinib (an inhibitor of multiple tyrosine kinases) in NF2-driven nonvestibular schwannoma and meningioma, data were needed on the use of brigatinib in patients with multiple types of progressive NF2-SWN tumors. METHODS: In this phase 2 platform trial with a basket design, patients who were 12 years of age or older with NF2-SWN and progressive tumors were treated with oral brigatinib at a dose of 180 mg daily. A central review committee evaluated one target tumor and up to five nontarget tumors in each patient. The primary outcome was radiographic response in target tumors. Key secondary outcomes were safety, response rate in all tumors, hearing response, and patient-reported outcomes. RESULTS: A total of 40 patients (median age, 26 years) with progressive target tumors (10 vestibular schwannomas, 8 nonvestibular schwannomas, 20 meningiomas, and 2 ependymomas) received treatment with brigatinib. After a median follow-up of 10.4 months, the percentage of tumors with a radiographic response was 10% (95% confidence interval [CI], 3 to 24) for target tumors and 23% (95% CI, 16 to 30) for all tumors; meningiomas and nonvestibular schwannomas had the greatest benefit. Annualized growth rates decreased for all tumor types during treatment. Hearing improvement occurred in 35% (95% CI, 20 to 53) of eligible ears. Exploratory analyses suggested a decrease in self-reported pain severity during treatment (-0.013 units per month; 95% CI, -0.002 to -0.029) on a scale from 0 (no pain) to 3 (severe pain). No grade 4 or 5 treatment-related adverse events were reported. CONCLUSIONS Brigatinib treatment resulted in radiographic responses in multiple tumor types and clinical benefit in a heavily pretreated cohort of patients with NF2-SWN. (Funded by the Children's Tumor Foundation and others; INTUITT-NF2 CIinicalTrials.gov number, NCT04374305.). [ABSTRACT FROM AUTHOR]

Neurofibromatosis type 2 (NF2) is a tumor suppressor gene implicated in various tumors, including mesothelioma, schwannomas, and meningioma. As a member of the ezrin, radixin, and moesin (ERM) family of proteins, merlin, which is encoded by NF2, regulates diverse cellular events and signalling pathways, such as the Hippo, mTOR, RAS, and cGAS-STING pathways. However, the biological role of NF2 in tumorigenesis has not been fully elucidated. Furthermore, cross-cancer mutations may exert distinct biological effects on tumorigenesis and treatment response. In addition to the functional inactivation of NF2, the codeficiency of other genes, such as cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B), BRCA1-associated protein-1 (BAP1), and large tumor suppressor 2 (LATS2), results in unique tumor characteristics that should be considered in clinical treatment decisions. Notably, several recent studies have explored the metabolic and immunological features associated with NF2, offering potential insights into tumor biology and the development of innovative therapeutic strategies. In this review, we consolidate the current knowledge on NF2 and examine the potential connection between cancer metabolism and tumor immunity in merlin-deficient malignancies. This review may provide a deeper understanding of the biological roles of NF2 and guide possible therapeutic avenues. [ABSTRACT FROM AUTHOR]

Neurofibromatosis Type II (NFII) is a genetic condition caused by loss of the NF2 gene, resulting in activation of the YAP/TAZ pathway and recurrent Schwann cell tumors, as well as meningiomas and ependymomas. Unfortunately, few pharmacological options are available for NFII. Here, we undertake a genome-wide CRISPR/Cas9 screen to search for synthetic-lethal genes that, when inhibited, cause death of NF2 mutant Schwann cells but not NF2 wildtype cells. We identify ACSL3 and G6PD as two synthetic-lethal partners for NF2, both involved in lipid biogenesis and cellular redox. We find that NF2 mutant Schwann cells are more oxidized than control cells, in part due to reduced expression of genes involved in NADPH generation such as ME1. Since G6PD and ME1 redundantly generate cytosolic NADPH, lack of either one is compatible with cell viability, but not down-regulation of both. Since genetic deficiency for G6PD is tolerated in the human population, G6PD could be a good pharmacological target for NFII. Few therapeutic options are available for patients with Neurofibromatosis Type II. Here, the authors identify G6PD as a potential pharmacological target and show that NF2 mutant Schwann cells are in an oxidized state and die when G6PD is inhibited. [ABSTRACT FROM AUTHOR]

Background: In most cases, intralabyrinthine schwannoma (ILS) occurs in patients with unilateral hearing deterioration or neurofibromatosis type II (NF II). The pattern of localization of these tumors varies but mostly affects the cochlea. Extirpation of the cochlear schwannoma, if hidden by the cochlea modiolus, is difficult under the aspect of complete removal. Therefore, a tissue removal device (TRD) was designed and tested in temporal bones. The principle of handling the new device is a pushing and pipe cleaner handling inside the cochlea. This present study aimed to describe the first in vivo experience with the newly developed TRD for removing cochlear intralabyrinthine schwannomas. Methods: In three patients, the TRD was used for the tumor removal of cochlear schwannomas. In two patients with a cochlear schwannoma in combination with a cochlea implantation and one patient suffering from NF II, a cochlear schwannoma was removed with the TRD. The access was performed with a posterior tympanotomy, an enlarged round window approach and an additional second turn access. The device was inserted and extracted gradually from the second turn access until the rings were visible in the second turn access. By pushing and pipe cleaner handling, the tumors were removed. An MRI control was performed on the day postoperatively with a T1 GAD sequence. Results: Tumor removal with the TRD was performed in a 15-min procedure without any complications. An MRI control confirmed complete removal on the postoperative day in all cases. Conclusions: In vivo handling of the device confirmed straightforward handling for the tumor removal. MRI scanning showed complete removal of the tumor by the TRD. [ABSTRACT FROM AUTHOR]

Objectives: Simultaneous removal and cochlear implantation (CI) have been reported in intralabyrinthine and intracochlear schwannoma. A wide range of postoperative hearing outcomes have been reported after CI in these cases. This study evaluated the outcomes of performing a simultaneous resection of Schwannoma in cochlea and cochlear implantation (CI), aiming to assess the effectiveness of this combined surgical approach for hearing rehabilitation with CI. Methods: This retrospective case series was conducted at a tertiary care center. The study included four consecutive patients with profound sensorineural hearing loss due to a mass inside the cochlea. These patients underwent simultaneous single-sided CI and tumor resection performed by the same surgeon. Preoperative and postoperative audiological assessments were conducted to evaluate the patients' hearing outcomes before and after the surgical intervention. Results: Simultaneous CI with tumor resection was successful in all cases. Two of the four patients had a unilateral tumor, while the other two had a bilateral tumor with the involvement of the internal auditory canal and cerebellopontine angle (neurofibromatosis type 2 (NF2)). In two cases of unilateral tumor, aided free-field pure tone average (PTA) was 26 dB, and 46 dB hearing level (HL), and word recognition score (WRS) at 65 dB was 40% and 68%, respectively, 3 months after surgery. In two cases of tumor with NF2, aided free-field PTA was 36 dB and 60 dB HL, and both cases showed 0% WRS at 65 dB 3 months after surgery. Conclusions: Simultaneous schwannoma excision and CI in patients with Schwannoma inside cochlea are surgically practical and safe. Postoperatively, there was a notable improvement in hearing in cases of sporadic schwannoma, regardless of the type of CI used. However, there was 0% WRS in the two NF2 patients with a mass in the internal auditory canal. [ABSTRACT FROM AUTHOR]

Simple Summary: The hallmark of NF2 is bilateral vestibular schwannomas, which progressively enlarge, leading to sensorineural hearing loss, tinnitus, facial weakness, and pain that translates to social impairment and clinical depression. To better understand disease progression and characterize treatment response, we developed a panel of five tests suitable for the mouse vestibular schwannoma model and investigated how tumor growth and treatment affect gait, coordination, and motor function. These methods, paired with hearing tests, enable a comprehensive evaluation of tumor-induced neurological deficits and facilitate the assessment of the effectiveness of novel therapeutics to improve NF2 treatments. NF2-related Schwannomatosis (NF2-SWN) is a disease that needs new solutions. The hallmark of NF2-SWN, a dominantly inherited neoplasia syndrome, is bilateral vestibular schwannomas (VSs), which progressively enlarge, leading to sensorineural hearing loss, tinnitus, facial weakness, and pain that translates to social impairment and clinical depression. Standard treatments for growing VSs include surgery and radiation therapy (RT); however, both carry the risk of further nerve damage that can result in deafness and facial palsy. The resultant suffering and debility, in combination with the paucity of therapeutic options, make the effective treatment of NF2-SWN a major unmet medical need. A better understanding of these mechanisms is essential to developing novel therapeutic targets to control tumor growth and improve patients' quality of life. Previously, we developed the first orthotopic cerebellopontine angle mouse model of VSs, which faithfully mimics tumor-induced hearing loss. In this model, we observed that mice exhibit symptoms of ataxia and vestibular dysfunction. Therefore, we further developed a panel of five tests suitable for the mouse VS model and investigated how tumor growth and treatment affect gait, coordination, and motor function. Using this panel of ataxia tests, we demonstrated that both ataxia and motor function deteriorated concomitantly with tumor progression. We further demonstrated that (i) treatment with anti-VEGF resulted in tumor size reduction, mitigated ataxia, and improved rotarod performance; (ii) treatment with crizotinib stabilized tumor growth and led to improvements in both ataxia and rotarod performance; and (iii) treatment with losartan did not impact tumor growth nor ameliorate ataxia or motor function. Our studies demonstrated that these methods, paired with hearing tests, enable a comprehensive evaluation of tumor-induced neurological deficits and facilitate the assessment of the effectiveness of novel therapeutics to improve NF2 treatments. [ABSTRACT FROM AUTHOR]

Purpose: Tethered spinal cord syndrome (TCS) is characterized by cutaneous attachments on the filum terminale that stretch the spinal cord, leading to musculoskeletal and urogenital sequelae. While the neurocutaneous associations with TCS remain undefined, a recent study reports a high incidence of TCS among a pediatric neurofibromatosis (NF) cohort. This present study utilizes a population-level database to estimate TCS incidence among pediatric patients with neurofibromatosis types 1 and 2 (NF1, NF2). Methods: The TriNetX Research Network was queried to identify patients diagnosed with NF and/or TCS before the age of 21. Symptomatic TCS requiring surgical intervention was identified using corresponding procedural codes within 12 months following TCS diagnosis. Odds ratios (OR) were calculated to measure the associations of NF1/NF2 with TCS. Results: 19,426 pediatric NF patients were evaluated (NF1: 18,383, NF2: 1042). The average ages of TCS diagnosis among NF1, NF2, and non-NF patients were 12, 16, and 9 years, respectively. The incidence of TCS was 1.2% in NF1 patients and 7.3% in NF2 patients, compared to 0.074% in the general population. The associations of NF incidence with TCS were significantly increased in both NF1 (OR 16.42; 14.38–18.76) and NF2 (OR 105.58; 83.56–133.40) patients compared to the general population. Symptomatic TCS requiring surgical intervention was not significantly associated with NF1/NF2 patients compared to the general TCS population. Conclusion: This analysis demonstrates a high incidence of TCS but delayed intervention in pediatric NF patients. Considering TCS counseling, spinal MRI, and earlier intervention may be warranted for NF patients experiencing musculoskeletal symptomatology. [ABSTRACT FROM AUTHOR]

Schwannomas are common benign tumours arising from the myelin sheath of peripheral nerves. These tumours are usually located in the intradural and extramedullary regions. The common sites are cervical (58%) and thoracic region (32%), followed by the lumbar region (10%). Intramedullary location is rare and if present, is usually associated with neurofibromatosis 1 and 2 (NF-1 and 2). Intramedullary brainstem schwannomas without NF are uncommon, and to the best of the authors' knowledge, only 19 cases have been reported to date. It was first described by James Watson Kernohan, an Irish-American pathologist, in 1931. The rarity of these tumours in this location is due to the absence of Schwann cells in this area. There are several hypotheses postulating the presence of these tumours in this location. The exact cause is not yet known. The authors here present a case of intramedullary brainstem ancient schwannoma with an unusual clinicoradiological presentation, which raised suspicion of Glioma with the possibility of Astrocytoma. The patient presented with right-sided neck stiffness and shoulder pain for a period of four months. Total excision of the tumour was performed, and the postoperative period was uneventful with clinical improvement in the patient. Histomorphology raised the suspicion of a tumour of glial origin with the possibility of Astrocytoma; Immunohistochemistry (IHC) helped in reaching the definitive diagnosis of Ancient Schwannoma. Thus, a combined approach of clinicoradiological, as well as histomorphology and IHC, is essential for a definitive diagnosis of these tumours. Future multicentric studies are required to elucidate the pathogenesis of the location of these tumours. [ABSTRACT FROM AUTHOR]

Introduction: Programmed death‐ligand 1 (PD‐L1) expression is an immune evasion mechanism that has been demonstrated in many tumors and is commonly associated with a poor prognosis. Over the years, anti‐PD‐L1 agents have gained attention as novel anticancer therapeutics that induce durable tumor regression in numerous malignancies. They may be a new treatment choice for neurofibromatosis type 2 (NF2) patients. Aims: The aims of this study were to detect the expression of PD‐L1 in NF2‐associated meningiomas, explore the effect of PD‐L1 downregulation on tumor cell characteristics and T‐cell functions, and investigate the possible pathways that regulate PD‐L1 expression to further dissect the possible mechanism of immune suppression in NF2 tumors and to provide new treatment options for NF2 patients. Results: PD‐L1 is heterogeneously expressed in NF2‐associated meningiomas. After PD‐L1 knockdown in NF2‐associated meningioma cells, tumor cell proliferation was significantly inhibited, and the apoptosis rate was elevated. When T cells were cocultured with siPD‐L1‐transfected NF2‐associated meningioma cells, the expression of CD69 on both CD4+ and CD8+ T cells was partly reversed, and the capacity of CD8+ T cells to kill siPD‐L1‐transfected tumor cells was partly restored. Results also showed that the PI3K–AKT–mTOR pathway regulates PD‐L1 expression, and the mTOR inhibitor rapamycin rapidly and persistently suppresses PD‐L1 expression. In vivo experimental results suggested that anti‐PD‐L1 antibody may have a synergetic effect with the mTOR inhibitor in reducing tumor cell proliferation and that reduced PD‐L1 expression could contribute to antitumor efficacy. Conclusions: Targeting PD‐L1 could be helpful for restoring the function of tumor‐infiltrating lymphocytes and inducing apoptosis to inhibit tumor proliferation in NF2‐associated meningiomas. Dissecting the mechanisms of the PD‐L1‐driven tumorigenesis of NF2‐associated meningioma will help to improve our understanding of the mechanisms underlying tumor progression and could facilitate further refinement of current therapies to improve the treatment of NF2 patients. [ABSTRACT FROM AUTHOR]

Neurofibromatosis type 2 (NF2)-related schwannomatosis is a rare autosomal dominant monogenic disorder caused by mutations in the NF2 gene. The hallmarks of NF2-related schwannomatosis are bilateral vestibular schwannomas (VS). The current treatment options for NF2-related schwannomatosis, such as observation with serial imaging, surgery, radiotherapy, and pharmacotherapies, have shown limited effectiveness and serious complications. Therefore, there is a critical demand for novel effective treatments. Gene therapy, which has made significant advancements in treating genetic diseases, holds promise for the treatment of this disease. This review covers the genetic pathogenesis of NF2-related schwannomatosis, the latest progress in gene therapy strategies, current challenges, and future directions of gene therapy for NF2-related schwannomatosis. [ABSTRACT FROM AUTHOR]

Objective: Vestibular schwannomas (VS), benign tumors stemming from the eighth cranial nerve's Schwann cells, are associated with Merlin gene mutations, inflammation, and the tumor microenvironment (TME), influencing tumor initiation, maintenance, and potential neural dysfunction. Understanding TME composition holds promise for systemic therapeutic interventions, particularly for NF2-related schwannomatosis. Methodology: A retrospective analysis of paraffin-embedded tissue from 40 patients (2013-2020), evenly divided by neurofibromatosis type 2 status, with further stratification based on magnetic resonance imaging (MRI) progression and hearing function. Immunohistochemistry assessed TME components, including T-cell markers (CD4, CD8, CD25), NK cells (CD7), and macrophages (CD14, CD68, CD163, CCR2). Fiji software facilitated image analysis. Results: T-cell markers (CD4, CD8, CD7) exhibited low expression in VS, with no significant NF2-associated vs. sporadic distinctions. Macrophage-related markers (CD14, CD68, CD163, CCR2) showed significantly higher expression (CD14: p = 0.0187, CD68: p < 0.0001, CD163: p = 0.0006, CCR2: p < 0.0001). CCR2 and CD163 significantly differed between NF2-associated and sporadic VS. iNOS, an M1-macrophage marker, was downregulated. CD25, a regulatory T-cell marker, correlated significantly with tumor growth dynamics (p = 0.016). Discussion: Immune cells, notably monocytes and macrophages, crucially contribute to VS pathogenesis in both NF2-associated and sporadic cases. Significant differences in CCR2 and CD163 expression suggest distinct immune responses. Regulatory T-cells may serve as growth dynamic markers. These findings highlight immune cells as potential biomarkers and therapeutic targets for managing VS. [ABSTRACT FROM AUTHOR]